Abstract: Herein is disclosed a sensor for noninvasive measurement of the partial pressure of CO2 (pCO2) in the skin of a human. The sensor comprises a housing, a gas measuring chamber for measuring gases, at least one chimney for communication of gases diffusing through the skin to the gas measuring chamber, a broad band light source transmitting light into the gas measuring chamber and a detector system comprising a first and a second photodetector. The first photodetector detects light at a wavelength wherein CO2 absorbs light and the second photodetector acts as a zero reference detector by measuring light in a freeband where no gases absorb light.

Abstract: The proposed invention provides a method of monitoring the dry cleaning progress of a transcutaneous sensor having an electrode for measuring pCO2 and an electrode for measuring pO2, both electrodes opening into a measuring surface of the sensor. The method comprises receiving an AC signal from the pCO2 electrode, initiating a cleaning of the sensor, and monitoring the cleaning progress by analyzing AC signals subsequently received from the pCO2 electrode.

Abstract: The proposed invention provides a method of monitoring the dry cleaning progress of a transcutaneous sensor having an electrode for measuring pCO2 and an electrode for measuring pO2, both electrodes opening into a measuring surface of the sensor. The method comprises receiving an AC signal from the pCO2 electrode, initiating a cleaning of the sensor, and monitoring the cleaning progress by analyzing AC signals subsequently received from the pCO2 electrode.

Abstract: In a process for measuring partial transcutaneous CO2 pressure on an earlobe by means of a sensor having a measuring device for measuring the partial transcutaneous CO2 pressure and a heating system for heating a sensor contact surface for contact with the earlobe, the sensor contact surface is heated. During a first phase, the sensor contact surface is kept at an elevated temperature of at least 41.5° C. in order to prevent the measured value of partial transcutaneous CO2 pressure from exceeding, due to the measurement process itself, the partial transcutaneous CO2 pressure achieved after stabilization. The temperature of the sensor contact surface is then reduced to between 37° C. and 41° C. This facilitates considerably faster evaluation of the measured values.